pub fn opening_split(s: &str) -> Option<(usize, usize)>Expand description
Where a chapter’s first paragraph splits for a drop cap, as byte offsets
into s: (initial_end, lead_in_end). The initial runs up to and
including the first letter or digit (so it carries any opening quote
before it); the lead-in is the rest of that word and two more
whitespace-separated words (a lone dash counts as a word), or all of s
if there are fewer. None when s has no letter or digit. Print and
EPUB both split with this, so they cannot disagree; each decides for
itself what may stand before the letter.